Hi
Thanks for data
df4$c3[df4$id==2] <- df4$c2[df4$id==2]
is one option
df4$c3 <- ifelse(df4$id==2, df4$c2, df4$c3)
If you have NA values you shall use which like in
sel <- which(df4$id==2)
df4$c3[sel] <- df4$c2[sel]
Cheers
Petr
> -----Original Message-----
> From: R-help [mailto:r-help-bounces at r-project.org] On Behalf Of Kuma
> Raj
> Sent: Monday, March 23, 2015 1:59 PM
> To: r-help at r-project.org
> Subject: [R] Replace a column value on condition
>
> I want to replace column c3 with values from column c2 whenever values
> of column Id are 2. In stata I could use replace c3 = c2 if id ==2.
> How could I do that in R?
>
> Thanks
>
>
> Sample data found below:
>
> > dput(df4)
> structure(list(c2 = c(42L, 42L, 47L, 47L, 55L, 55L, 36L, 36L, 61L,
> 61L), c3 = c(68L, 59L, 68L, 50L, 62L, 50L, 63L, 45L, 65L, 45L), id >
c(1, 2, 1, 2, 1, 2, 1, 2, 1, 2)), datalabel = "Written by
> R. ", time.stamp = "23 Mar 2015 13:54", .Names
= c("c2",
> "c3", "id"), formats = c("%9.0g",
"%9.0g", "%9.0g"), types = c(253L,
> 253L, 255L), val.labels = c("", "", ""),
var.labels = c("", "", ""),
> row.names = c("1", "2", "3", "4",
"5", "6", "7", "8", "9",
"10"),
> version = 12L, class = "data.frame")
>
> ______________________________________________
> R-help at r-project.org mailing list -- To UNSUBSCRIBE and more, see
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> PLEASE do read the posting guide http://www.R-project.org/posting-
> guide.html
> and provide commented, minimal, self-contained, reproducible code.
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